Privacy Preserving Billing for E-Shopping in Online Marketing System

several daily life applications such as payment, access control, ticketing, and e-passport, which requires strong security and privacy mechanisms. Hence there is a demanding urge to address these issues in the light of some mechanism which can make the technology excel. . In recent years, various mobile terminals equipped with NFC (Near Field Communication) have been released. The combination of NFC with smart devices has led to widening the utilization range of NFC. It is expected to replace credit cards in electronic payment, especially. In this regard, security issues need to be addressed to vitalize NFC electronic payment. The NFC security standards currently being applied require the use of user's public key at a fixed value in the process of key agreement. For key agreement NFC algorithm is used. This paper proposes a method provide a conditional anonymity using dynamic public key to solve this problem. Also it defines PDU for the conditional anonymity, so that the user can use the dynamic public key selectively. Through this, the user can protect privacy and can verify identity through a trusted authority if necessary.